[PATCH net-next] selftests: hw-net: rss-input-xfrm: try to enable the xfrm at the start

[Jakub Kicinski <kuba@kernel.org>]

The test currently SKIPs if the symmetric RSS xfrm is not enabled
by default. This leads to spurious SKIPs in the Intel CI reporting
results to NIPA.

Testing on CX7:

 # ./drivers/net/hw/rss_input_xfrm.py
  TAP version 13
  1..2
  ok 1 rss_input_xfrm.test_rss_input_xfrm_ipv4 # SKIP Test requires IPv4 connectivity
  # Sym input xfrm already enabled: {'sym-or-xor'}
  ok 2 rss_input_xfrm.test_rss_input_xfrm_ipv6
  # Totals: pass:1 fail:0 xfail:0 xpass:0 skip:1 error:0

 # ethtool -X eth0 xfrm none

 # ./drivers/net/hw/rss_input_xfrm.py
  TAP version 13
  1..2
  ok 1 rss_input_xfrm.test_rss_input_xfrm_ipv4 # SKIP Test requires IPv4 connectivity
  # Sym input xfrm configured: {'sym-or-xor'}
  ok 2 rss_input_xfrm.test_rss_input_xfrm_ipv6
  # Totals: pass:1 fail:0 xfail:0 xpass:0 skip:1 error:0

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
CC: shuah@kernel.org
CC: gal@nvidia.com
CC: noren@nvidia.com
CC: linux-kselftest@vger.kernel.org
---
 .../drivers/net/hw/rss_input_xfrm.py          | 44 ++++++++++++++++---
 1 file changed, 38 insertions(+), 6 deletions(-)

diff --git a/tools/testing/selftests/drivers/net/hw/rss_input_xfrm.py b/tools/testing/selftests/drivers/net/hw/rss_input_xfrm.py
index 72880e388478..503f1a2a2872 100755
--- a/tools/testing/selftests/drivers/net/hw/rss_input_xfrm.py
+++ b/tools/testing/selftests/drivers/net/hw/rss_input_xfrm.py
@@ -5,9 +5,9 @@ import multiprocessing
 import socket
 from lib.py import ksft_run, ksft_exit, ksft_eq, ksft_ge, cmd, fd_read_timeout
 from lib.py import NetDrvEpEnv
-from lib.py import EthtoolFamily, NetdevFamily
+from lib.py import EthtoolFamily, NetdevFamily, NlError
 from lib.py import KsftSkipEx, KsftFailEx
-from lib.py import rand_port
+from lib.py import defer, ksft_pr, rand_port
 
 
 def traffic(cfg, local_port, remote_port, ipver):
@@ -21,6 +21,40 @@ from lib.py import rand_port
     return sock.getsockopt(socket.SOL_SOCKET, socket.SO_INCOMING_CPU)
 
 
+def _rss_input_xfrm_try_enable(cfg):
+    """
+    Check if symmetric input-xfrm is already enabled, if not try to enable it
+    and register a cleanup.
+    """
+    rss = cfg.ethnl.rss_get({'header': {'dev-name': cfg.ifname}})
+    orig_xfrm = rss.get('input-xfrm', set())
+    sym_xfrm = set(filter(lambda x: 'sym' in x, orig_xfrm))
+
+    if sym_xfrm:
+        ksft_pr("Sym input xfrm already enabled:", sym_xfrm)
+        return sym_xfrm
+
+    for xfrm in cfg.ethnl.consts["input-xfrm"].entries:
+        # Skip non-symmetric transforms
+        if "sym" not in xfrm:
+            continue
+
+        try_xfrm = {xfrm} | orig_xfrm
+        try:
+            cfg.ethnl.rss_set({"header": {"dev-index": cfg.ifindex},
+                               "input-xfrm": try_xfrm})
+        except NlError:
+            continue
+
+        ksft_pr("Sym input xfrm configured:", try_xfrm)
+        defer(cfg.ethnl.rss_set,
+              {"header": {"dev-index": cfg.ifindex},
+               "input-xfrm": orig_xfrm})
+        return {xfrm}
+
+    return set()
+
+
 def test_rss_input_xfrm(cfg, ipver):
     """
     Test symmetric input_xfrm.
@@ -37,12 +71,10 @@ from lib.py import rand_port
     if not hasattr(socket, "SO_INCOMING_CPU"):
         raise KsftSkipEx("socket.SO_INCOMING_CPU was added in Python 3.11")
 
-    rss = cfg.ethnl.rss_get({'header': {'dev-name': cfg.ifname}})
-    input_xfrm = set(filter(lambda x: 'sym' in x, rss.get('input-xfrm', {})))
-
     # Check for symmetric xor/or-xor
+    input_xfrm = _rss_input_xfrm_try_enable(cfg)
     if not input_xfrm:
-        raise KsftSkipEx("Symmetric RSS hash not requested")
+        raise KsftSkipEx("Symmetric RSS hash not supported by device")
 
     cpus = set()
     successful = 0
-- 
2.52.0